本論文は、家族政策が合計特殊出生率に与える影響について考察する。家族政策は、子育て支援のみならず、女性就業支援、男女平等なども含めて論じる。一般的に、女性就業率が高くなると、合計特殊出生率の低下を招くと言われたが、女性就業率と合計特殊出生率の両立の可能性について考察する。一方、世界各国のデータを見ると、合計特殊出生率は、一人当たりGDPが高い国ほど低いと見られるが、時系列で見た場合、経済発展がある成熟段階に達すると、一人当たりGDPが高くなるにつれ、合計特殊出生率がU字型に回復する傾向がある。合計特殊出生率の低下を経験してきた一人当たりGDPの高い国及び地域、そして発展途上にある東南アジアと比較し、その原因についても考察する。In the industrial stage of economic development, when the female labour force participation rate increases, the total fertility rate (TFR) tends to decrease. In the case of Japan, the total fertility rate (TFR) peaked at 4.4 after the Second World War. Since then, the TFR followed a declining trend and it reached a record low point at 1.26 in 2005 (Chart 1 in the Japanese text).It is not only Japan but also in most industrial countries that the TFR has followed a declining trend at least for a certain period. However, when female participation in the labour market and the existence of dual breadwinners become seen as normal phenomena, there is a good possibility that the TFR will begin to recover.“ The Nordic combination of high levels of female labour force participation with relatively high levels of fertility, may suggest that a sustainable level of fertility is compatible with gender equality. In Japan and Korea in Asia, and in Germany, Italy, Spain and the former communist countries in Europe, the TFR has remained at a low level, while in the Nordic countries, in the US, France and UK the movement of the TFR has changed from a decreasing trend to an upward trend.This paper sets out to explain the main possible reasons that make it possible to divide highly industrial countries into two groups, namely, the low TFR countries and the countries that have succeeded in recovering or in keeping the TFR at a fairly high level.By using similar reasoning, it will be possible to explain the U-shaped behaviour of TFR as an economy develops. If we express the TFR on the vertical axis and an indicator of economic development on the horizontal axis, a U-shaped line or V-shaped line will appear as shown in Chart 1.However, the U-shaped behaviour shown above does not take place automatically. We have assumed that there are three main possible reasons to explain the change in the trend of TFR behaviour and the difference in the TFR between the lowest TFR countries and the relatively higher TFR countries among the industrialized countries.The first reason to explain the U-shaped behaviour is that of changes in“ the traditional status relationships” and in conservative attitudes and practices aimed at maintaining these relationships. In particular, it is essential to change the differential treatment of female workers and that of male workers. Changing differential status relationships between regular employees and part-time employees is also important.If the changes mentioned above do not take places, the increase in the female labour participation rate or the ratio of female employees to total employees will probably entail a decline in the TFR. We assume that the conflict between increasing female participation in the labour market and unchanging conservative status relationships will bring about a decreasing TFR and that renovations in conservative status relationships have positive effects on the TFR and that the reforms in conservative status relationship will have positive effects on the TFR.Secondly, we have assumed that active family policies have positive effects on the TFR, other things being equal.Thirdly, favourable economic performance such as higher economic growth, lower unemployment rate and bright economic prospects in future will have favourable effects on the TFR, other things being equal.In this paper, we suggest that it is possible to predict the TFR in the near future by observing the behavior of the “marginal” fertility ratio (the difference of TFR between the year and that of the preceding year), for marginal ratio precedes the average ratio as Chart 2 in the case of Japan suggests.In the last section of this paper we will try to show the data to support the above hypothesis, especially from the cases of high GDP per capita countries and the cases of the developing countries in Southeast Asia.In 2009 Myrskylä、Mokko, Hans-Peter Kohler Francesko& C. Billari published a paper“ Advances in development reverse fertility declines” Nature, August 2009. They suggest that including developing countries a reversed J shaped curve will be observed. Their paper in 2009 is more comprehensive including less developed countries and used more comprehensive indicators than Maruo’ papers in 2006. However, their findings suggest as far as highly developed countries are concerned the V shaped behavior is observed.